Apparatus for dressing a grinding wheel



Oct. 29, 1968 w. voLLMAN 3,407,801

APPARATUS FOR DRESSING A GRINDING WHEEL Filed June 6, 1966 '7 Sheets-Sheet l .u l l Illlllll WAL TER VLLMAN INVENTOR.

ORA/EY Oct. 29, 1968 w. voLLMAN -APPARATUS FOR DRESSING A GRINDING WHEEL Filed June e, 196e 7 Sheets--Sheel 2 WALTER VOLLMA/V INVENTOR TOR/VE Y Oct. 29, 1968 w. VOLLMAN APPARATUS FOR DRESSING A GRNDING WHEEL 7 Sheets- Sheet 5 Filed June 6. 1966 Nul @nl h n@ Q WALTER v01. LMA/v INVENTOR j as romver Oct` 29, 1968 Filed June 6, 1966 K ...mm

W. VOLLMAN APPARATUS FOR DRESSING A GRINDING WHEEL '7 Sheets- Sheet 4 WAL TER VOI. LMA/V INVENTOR.

4 RNEY Oct, 29, 1968 w.vol 1 MAN APPARATUS FOR DRESSING A GRINDING WHEEL Filed June 6, 1966 7 Sheets-Sheet 5 ,180' Hil- I /90 WALTER VOLL/WAN INVENTOR.

Oct. 29, 1968 w. voLLMAN 3,407,801

APPARATUS FOR DRESSING A GRINDING WHEEL Filed June 6, 1966 '7 Sheets-Sheet 6 WAL TER VOL LMAN INVENTOR.

ORNE Y Oct. 29, 1968 w. VOLLMAN 3,407,801,

APPARATUS FOR DRESSING A GRINDING WHEEL Filed June 6, 1966 7 Sheets-Sheet 7 "mit lf WiiiimiiliiiiiiHmmmimmunminimiliiiiimlllli 3| WAL TER VOL LMN INVENTOR.

United States Patent- O "ice 3,407,801 APPARATUS FOR DRESSING A GRINDING WHEEL Walter Wellman, 207 Southern Blvd.,

, Chatham, NJ. 079,28 Filed June 6, 1966, Ser. No. 555,532` Claims. (Cl. 12S-11) This invention relates to apparatus for dressing a grinding wheel and more particularly to apparatus attach'able to a grinding machine and manually operable to impart a predetermined configuration to thesurface of an abrasive wheel carried by the machine'.v

In 'Various-machine shop operations, particularly in tool and vdie making, itis necessary to generate `a surface of complex configuration in a workpiece. Generally, this can be effected advantageously and precisely by means of a grinding operation. This is accomplished by making a template having a reverse, or reciprocal configuration to that desired in the workpiece. The template is utilized vas a guide for a dressing tool having a diamond point which is brought into contact with the rotating grinding wheel, thereby producing a corresponding configuration of the wheel surface. Thereafter, the grinding wheel is used to generate the desired surface configuration inthe workpiece.

Various forms of wheel dressing apparatus are available. Certain prior apparatus incorporate pantograph or optical systems, which systems incorporate a magnification factor, -for example, a ratio of 10 to 1 'between the movement of a tracing stylus engaging a template and the diamond point engaging the grinding wheel. The require- Iment for making the template of substantially increased size often is difficult and expensive. Further, apparatus of this class is expensive and large. In order to handle a one inch wide grinding wheel, a pantograph wheel dresser is of such large construction that it is not good practice to mount such device on a small surface grinder. Other prior apparatus is unsatisfactory for operations requiring a high degree of precision, either by reason of the con struction and arrangement of the component parts thereof, or the normal variations in the alignment of the machine slides and wheel spindle. Generally, the longitudinal and cross slides on a surface grinder are not perfectly square.

j Apparatus made in accordance with this invention is of` a sturdy construction, operates on a 1,;1 ratio of movement between the tracing stylus and the diamond `point engaging the grinding wheel, and is not restricted for mounting on `a particular style, `size or make of grinding machine. Suitable adjustments are provided to compensate for all variations encountered in properly mounting the apparatus on a grinding machine, including errors in the alignment of the machine slides and wheel spindle, so that the accuracy of the surface configuration imparted tothe wheel will correspond to that of the template within 1.0002 inch. Further, the apparatus is so arranged that it can remain mounted on the machine but rotated to a noninterfering position relative to the wheel and the machine slides, without loss of adjustment, whereby the dressed Wheel can be brought into working engagement Iwith the workpiece. This facilitates redressing of the wheel, if necessary, without loss of the working alignment of the wheel and the workpiece. v

An object of this invention is the provision of improved apparatus for mounting on a grinding machine for the purpose of imparting a predetermined configuration'to the Surface of the grinding wheel. l

An object of this invention is the provision of apparatus `of the class having a diamond point movable into engagement with a grinding wheel in correspondence with movement of a tracingstylus over a template, which apparatus operates on a 151 `ratio of movement between the tracingstylus and the diamond point and ywherein thesur- 3,407,801 Ratented Oct. 29, 1968 -face configuration imparted to the wheel corresponds to that ofthe template within 1.0002 inch.

A n object of this invention is'the provision of apparatus for dressinga grinding gwheel, which apparatus com' prises a template having Aformed thereon :a surface of the predetermined configuration, adjustable means for Supporting the template in predetermined alignment with the peripheral surface of the grinding wheel, a tracing stylus and a diamond point, and means mounting `the stylus .and point for pivotal and linear movement relative to thestemplate thereby to impartjto thewheel a surface configuration corresponding to that ofthe template. i.

An object'of this invention is to provision of apparatus for imparting a predetermined configurationl torthe` surface of .an abrasive wheel carried by a grindingnma chine, which apparatus comprises a support for attachment toA the machine, means for securing to the support 'a template having a surface of the predetermined configuration, a rstylus mounted for tracing engagement with the template surface, a diamond point mounted for simultane-` ous and direct movement with `the stylus, and manually adjustable means for adjusting the ,positions of thetemplate and the stylus relative to the wheel. An object of this invention is the provision of appara tus Vcomprising means for mounting the apparatuson a grinding machine, lmeans for securing to the,y apparatus a template of predetermined surface configuration, means for moving the template in two directions in a plane parallel to that of the machine cross slides, a plurality of arms pivotally-coupled together and rotatable about individual axes, means for adjusting each axis to be perpendicular to the machine cross slides, and a rotatable: tool ,bar carried by one of the said arms, said tool bar carrying a diamond point for engaging the grinding wheelf and azstylus for engaging the template. n

These and other objects and advantages will become apparent from the following description when taken with the accompanying drawings. It will be understood, however, that the drawingsare for purposes of illustration and are not to be construed as defining the scopeor limits of the invention, reference being had for the latter purpose to the claims appended hereto.

In the drawings wherein like reference characters denote like parts in the several views:

FIGURE 1 is a front elevational view of apparatus made in accordance with this invention;

FIGURE 2 is"a corresponding top plan view thereof;

FIGURE 3 is a fragmentary front elevational view corresponding to FIGURE 1 but showing the two vertical pivot arms rotated to the aligned or extended position and the tracing stylus rotated degrees counterclockwise from the position shown "in FIGURE 1;

FIGURE v4 is a fragmentary cross-sectional view taken along the line 44 of FIGURE 2 and showing the two locking screws and the4 pivot pin forming a rotational axis for the L-shaped mounting bracket carried by the mounting block-and serving as the support for certain components of the apparatus; l

FIGURE 5 is an enlarged cross-sectiona1 view taken along the line 5--5 of FIGURE 1 to show the arrangement for effecting a rotary adjustment: of the L-shaped .bracket relative to -the mounting block;

FIGURE 6 is a fragmentary top plan view showing the transverse support plater secured to the mounting block, which support `plate carries the -remaining components of the apparatus;

FIGURE 7 is a cross-sectional view taken along the line 7-7 of FIGURE 6 to show the means for effecting a vertical angular adjustment of the transverse support plate'relative tothemounting block; n

FIGURE 8 is a cross-sectional view taken along the line 8 8 of FIGURE 6;

FIGURE 9 is a vertical cross-sectional view taken along the line 9-9 of FIGURE 3 and showing the pivot pin and the two adjusting screws for effecting a perpendicular adjustment of the vertical block relative to the transverse support plate;

FIGURE 10 is an enlarged, transverse cross-sectional view taken along the lines 10-10 of FIGURE 3 showing the arrangement for clampingly securing a pivot shaft to the vertical block;

FIGURE 11 is an enlarged, vertical cross-sectional view taken along the line 11-11 of FIGURE 3 showing the construction of the pivot shaft, bearings and dust seals;

FIGURE 12 is a transverse cross-sectional view taken along the line 12--12 of FIGURE l1;

FIGURE 13 is an enlarged cross-sectional view taken along the line 13--13 of FIGURE 3 showing the arrangement for removably securing the tool bar, carrying the stylus and the diamond point, in operative position on the apparatus;

FIGURE 14 is an enlarged cross-sectional view taken along the line 14-14 of FIGURE 2 showing the arrangement for securing the template to the cross slide of the apparatus;

FIGURE 15 is a cross-sectional view taken along the line 15-15 of FIGURE 14, showing the arrangement for adjusting the cross slide relative to the supporting cross head;

FIGURE 16 is a fragmentary view corresponding to FIGURE 14 but taken along another plane to show the means for effecting adjustment of the template carried by the cross slide;

FIGURE 17 is a longitudinal cross-sectional view taken along the line 17-17 of FIGURE 2 showing the micrometer mechanism for effecting a calibrated, longitudinal adjustment of the horizontal slide of the apparatus;

FIGURE 18 is a cross-sectional view taken along the line 18-18 of FIGURE 17 showing the calibration markings carried by the head of one of the adjusting screws of the micrometer mechanism;

FIGURE 19 is an enlarged cross-sectional view taken along the line 19-19 of FIGURE 1 and showing the L-shaped mounting bracket, the longitudinal slide and its supporting slide block, and the slide-adjusting mechanism;

FIGURE 20 is a fragmentary cross-sectional view taken along the line 20-20 of FIGURE 1 and showing the mounting of the longitudinal slide on the supporting slide head; and

FIGURE 21 is an enlarged, fragmentary, rear elevational view of the micrometer mechanism.

Reference now is made to FIGURES 1 and 2. Although apparatus made in accordance with this invention may be provided with various mounting means designed for the attachment of the apparatus to a particular grinding machine, there is shown, in FIGURE l, a mounting block 10 having an extended, flat upper surface and provided with a through hole 11. This hole is intersected by a radial slot formed in an integral flange portion, whereby the block can be secured to the spindle housing of a grinding machine by a plurality 0f screws 12, only one such screw being visible in this particular view. The mounting block is secured to the spindle housing with the flat, upper surface parallel to the cross slide of the grinding machine, such parallelism being determined by means of a suitable indicator. Preferably, the mounting block has a substantial axial length, say, two inches, thereby to assure a positive attachment of the block to the spindle housing.

A sturdy, L-shaped mounting bracket, generally identified by the numeral 13, has a horizontal leg 14 (see FIGURE 2) resting upon and secured to the upper,

`fiat surface of the mounting block by the four locking screws 15. The Vertical leg 16, of the bracket (see FIG- URE l), has an outer surface substantially co-planar with the forward, vertical surface of the mounting block. As shown in FIGURE 4, which is a cross-sectional view taken along the line 4-4 of FIGURE 2, a pivot pin 18 is force-fitted into a hole formed in the mounting block 10 and extends through a close-fitting hole formed in horizontal leg 14 of the mounting bracket. Also, the locking screws 15 pas's through clearance holes formed in such bracket leg. Thus, upon loosening of the locking screws, the bracket is rotatable about the pivot pin to a limited extent determined by the size of the clearance holes. Such rotation of the mounting bracket is effected by means of a pair of adjusting screws, the forward adjusting screw 19 being visible in front elevational view of FIGURE 1 and the rear screw 20 lbeing visible in the top plan view of FIGURE 2. This adjustment arrangement will best be understood by reference to FIGURE 5, which is an enlarged, cross-sectional view taken along the line 5 5 of FIGURE 1. Horizontally-aligned, threaded holes are formed in the mounting block 10 for receiving the threaded Shanks of the adjusting screws 19 and 20, each such threaded hole terminating in a bore for accommodating the head of the associated screw. To form the bores, the bracket leg 14 and the block 10 are clamped together, in a 'suitable fixture, and the two bores are formed axially of the threaded holes. These bores have an initial diameter corresponding to that of the heads of the adjusting screws 19 and 20, and the major portion of each bore is formed in the mounting block 10. The block and the bracket leg are then separated and the arcuate wall portions in the bracket leg are milled to a somewhat increased diameter, thereby resulting in a clearance area for the screw heads, as shown. The bottom walls of these lbores form the shoulder portions 23 and 24. The bores on the mounting block 10 are then milled to an increased depth so that the resulting shoulder portions 21 and 22 are offset relative to the other shoulder portions 23 and 24 when the block and the bracket leg are assembled together, as shown. In FIGURE 5, the bracket leg is shown displaced to the right relative to the block. It will be seen that by loosening one 'screw and tightening the other, the bracket leg will be shifted to the right or left relative to the mounting block. Upon effecting a desired shift of the bracket leg, the loosened screw is tightened, thereby securing the leg in place. The described construction, wherein a major portion of the heads of the adjusting screws 19 and 20 are in engagement with the walls defining the bores in the mounting blocks 10, prevents the screw heads from bending, and possible shearing, under the pressure developed between the upper portions of the screw heads and the shoulders 23 and 24. Referring back to FIGURES 1 and 2, it will be apparent that the described manipulation of the adjusting screws 19 and 20 effects an angular movement of the mounting bracket about the pivot pin 18 when the locking screws 15 are loosened slightly. Subsequent tightening of the locking screws locks the bracket 13 securely in the desired position.

The described adjustment arrangement is for the purpose of aligning the vertical leg of the L-shaped mounting bracket parallel to the longitudinal machine slide disposed -below the grinding wheel, a portion of the grinding wheel being shown by the broken line 26 in FIGURE l. Those skilled in this art will understand that the grinding wheel is carried by a spindle projection through the hole 11 of the mounting block 10.

With continued reference to FIGURES 1 and 2, a longitudinal slide block 28 is rigidly secured to the vertical leg 16, of the L-shaped mounting bracket 13, by means of the four fastening screws 29, said slide block being provided with a dovetail groove for receiving the integral dovetail portion 30 of the longitudinal slide 31. A pair of thumb screws 32 serve to lock the slide to the slide block as Will be described in detail hereinbelow. A micrometer mechanism for effecting a calibrated adjustment of the slide along the supporting slide block comprises a pair of axially aligned screws 33 and 34 (respectively carried by the bifurcated ends 35, 36 of a block secured to the vertical surface of the L-shaped mounting bracket), a block 37 secured to the slide bar 31 by the screws 38, and a horizontally-extending bar 39 carrying a reference pointer 40, which bar is secured to the upstanding portion of the block 37 by the screw 41.

A better understanding of the construction and arrangement of the parts just identified will be had by reference to FIGURE 19, which is an enlarged, crosssectional View taken along the line 19--19 of FIGURE 1. Here is shown the I.shaped mounting bracket 13 having its horizontal leg 14 secured to the mounting block 10 by the fastening screws 15. The vertical leg 16, of this bracket, has an extended length. Also visible in this view is one of the four screws 29 which secure the longitudinal slide block 23 to the vertical bracket leg 16, said block slidably supporting the longitudinal slide 31 having the integral, dovetail portion 30 extending from the lower surface thereof. For purposes of precision and manufacturing economy, only the left and the bottom wall defining the matching dovetail channel are formed directly in the slide block 28. The right hand portion of the 'slide block is milled away, the full length of the block, to receive a plate 44 having the illustrated cross-sectional configuration. This plate is secured to the slide block 28 by five screws 45, see FIGURE 1, also FIGURE 20, which is a cross-sectional view taken along the line 20-20 of FIGURE 1 and drawn to the same scale as FIGURE 19. The upper, inner surface of the plate 44 forms the other oblique wall for the dovetail channel. It will be noted,

in FIGURE 19, that the rear wall of the slide bar 31 is spaced `from the bracket leg 16. Thus, upon loosening the thumb screws 32, the slide is slidable along the supporting slide block and is retained in a desired, set position by tightening these screws. It is here pointed out that in the construction and arrangements of these parts, there is a small clearance area between the bottom surface of the dovetail 311 and the bottom wall of the dovetail channel, also a slight clearance area between the `oblique surface of the dovetail and the proximate surface of the plate 44. Thus, there are only three bearing surfaces between the slide 31 and the supporting block 28, which bearing surfaces are identified by the letter X. These bearing surfaces can be formed with a high degree of precision and at a low production cost.

Also visible in the particular view of FIGURE 19, is one of the two screws 38, which secure the block 37 to the slide 31, and the horizontally-extending bar 39 which is secured to the upright portion of the block 37 by the screw 41. In FIGURE 19, the left portion of the horizontally-extending bar 39 is disposed behind the forward end of the bifurcated `block 46 which is secured to the vertical bracket arm 16 by two screws 47, see also FIG- URE 21, which is a fragmentary, rear elevational View of the micrometer mechanism. The upper portion of the block end 35 is of increased width and provided with a threaded hole receiving the threaded shank of the adjusting screw 33, see also FIGURE 1. The corresponding, other end of the bifurcated block 46 is provided with an aligned, threaded hole receiving the threaded shank of a pressure screw 34. The index pointer has an end extending into a hole formed in the upwardly projecting ear 48, formed integral with the horizontal block 39, said pointer being secured in place either by means of a force fit or by a set screw. Thus, the index pointer 40 'is disposed above the upper surface of the block end 35, see also FIGURES 1 and 21. The pointed, free end of the pointer 40 lies on a radius somewhat less than that of the knurled head of the adjusting screw 33.

With reference now to FIGURE 2, the horizontallydisposed bar 39 is positioned between the ends of the two screws 33 and 34 and such bar is secured to the slide 31. On the other hand, the supports for these screws are secured to the upright arm 16 of the L-shaped mounting bracket. Hence, a longitudinal displacement of the slide 31 is effected by means of these screws, one of which includes a spring-biased plunger for-eliminating backlash, as will now be described.

Referring to FIGURE 17, which is a cross-sectional view taken along the line 17-17 of FIGURE 2, the -pressure screw 34 has an axial bore formed therein, said bore terminating in a reduced-diameter hole. A plunger 50, having an integral collar 51, has an end 52 extending through such hole. A compression spring 53 encircles the plunger and the spaced, reduced-diameter tip of a set screw 54 which is threaded into the bore. The set screw affords adjustment of the initial, axial force exerted by the spring on the collar of the plunger. The associated adjusting screw 33 has a blunt end for engagement with the horizontal bar 39. Assuming that the screw 34 is rotatably advanced toward the bar 39, the plunger will be depressed so that its collar is no longer in engagement with the end wall of the screw 34. The plunger now will retain the bar 39 in engagement wwith the: end of the adjusting screw 33 irrespective of the direction of rotation of such screw, over a limited range. i

As shown in FIGURE 18, which a cross-sectional View taken along the line 13-18 of FIGURE 17, the inner surface of the head of the adjusting screw 33 has radial lines engraved thereon and forming a calibrated scale 55, the spacing of the scale lines corresponding to `a linear displacement of, say 0.001 inch of the screw. Referring again to FIGURE 1, it will now be apparent that a predetermined precise movement of the longitudinal slide 31, relative to its supporting `block 28, is obtained by rotating the adjusting screw 33 a corresponding angular extent as determined by reference to the end of the pointer 40 and the graduated scale formed on the inner surface of this screw head.

With continued reference to FIGURES 1 and 2, a cross head 57, comprising a base member 581 and end plates 59, 69, is rigidly secured to the right hand end of the longitudinal slide 31, each end plate being secured to opposite ends of the base member by two screws, the screws 61 associated with the side plate 59 `being visible in FIG URE 1. The cross head carries a cross slide 62 having integral, forwardly-extending ledges 63 and 64 between which a template 65 can be secured. The construction and assembly of these parts will be described hereinbelow. For the present, it is pointed out that sliding displacement of the cross slide 62 relative to the cross head 57 is effected by rotation of the aligned adjusting screws 66 and66, having enlarged, knurled heads.

FIGURE 14, which is an enlarged, cross-sectional view taken along the line 14-14 of FIGURE 2, shows the right end of the longitudinal slide 31 having the base member 58, of the cross head 57, secured thereto by the screw 67. Actually, the base member 58 is secured to the said slide 31 by three screws 67, as shown in FIGURE 15, which is a full, transverse, cross-sectional view taken along the plane 15-15 of FIGURE 14. The cross slide 62 has an integral dovetail portion extending from its inner surface, said dovetail portion having an integral tab 68 projecting into a lclearance channel 69 formed in and extending the full length of the base member 58. The right end of the base member 58, as viewed in FIGURE 14, has a vertical surface which is in sliding engagement with the dovetail portion of the cross slide 62 and an oblique surface corresponding to the lower part of the said dovetail portion. The upper portion of the Ibase member 58 is milled away to accommodate a plate 70 which plate is secured to the said base member by the three screws 71, see also FIGURE 15. As shown in FIGURE 15, the two adjusting screws 66 .and 66 extend through threaded holes formed in the end plates 59 and 60 andl into the channel 69 provided in the base member 58. These screws have reduced-diameter ends engaging the tab 68 which is integral with the cross slide. Thus, upon the simultaneous rotation of the screws 66 and 66', in the same direction, the tab 68 can be adjusted to a desired, relatively fixed 7 position. Such adjustment results in a corresponding movement of the cross slide 62, see FIGURE 14, transversely of the longitudinal slide 31.

With continued reference to FIGURE 14, the lower surface of the template 65 has milled therein a slot 73, which slot is defined by an arcuate base wall and vertical side walls. This slot is formed along the center line of the template. A locking screw 74 is received in a threaded hole formed in the lower ledge 63, of the cross slide 62, it being noted that a portion of this screw head extends above the upper surface of this ledge and into the slot of the template. The rear edge of the template abuts against two locating screws, one such screw 75 being visible in this view. These two locating screws are spaced on either side of the locking screw 74, are threaded in holes formed in the cross slide 62, and lie in a horizontal plane. Axially aligned with each locating screw is an arcuate channel formed in the upper surface of the ledge 63. This arrangement will 'be better understood by reference to FIGURE 16, which is a fragmentary cross-sectional view corresponding to FIGURE 14 but taken along a transverse plane passing through the axis of the identified locating screw 75. Here, the axially-aligned, arcuate channel is identified by the numeral 76. There also is shown the set screw 77 for securing the locating screw 75 in place. The template rests upon the upper surface of the ledge 63 and its inner side wall is brought into engagement with the two locating screws by the head of the locking screw 74 (see FIGURE 14) as the latter is threaded into the ledge 63 to the fullest possible extent. It will be apparent, then, that the outer side wall of the template can be oriented to lie in a given plane, relative to the cross slide 62, by adjustment of one or the other of the two locating screws. This adjustment of the template is for the purpose of aligning the outer side wall of the template in a vertical plane parallel to the peripheral surface of the grinding wheel. When once properly aligned, the template is secured in position by means of two vertical clamping screws 78, one such screw being visible in FIGURES 14 and 16 and the two such screws 'being visible in the plan view of FIGURE 2.

summarizing the description to this point, the various components of the apparatus and the various adjustment arrangements are for the purpose of establishing a precise alignment and movement of the template with respect to the grinding wheel. Referring to FIGURES 1 and 2, the mounting block is secured to the spindle housing of the grinding machine so that the longitudinal slide 31 will move in a plane precisely parallel to that of the machine longitudinal slide to which the work piece is secured. Such parallelism is determined by checking with a conventional indicator commonly available in a machine shop. Next, movement of the slide 31 in a plane parallel to the longitudinal slide of the grinding machine is established by means of the adjusting screws 19 and 20 which effect an angular movement of the longitudinal slide of the wheel dresser in a horizontal plane about the pivot pin 18. The means for checking this setting of the slide `will be described hereinbelow. The template 65 is firmly secured to the cross slide 62 in a desired position, which position is adjustable, and such template is movable in a plane normal to that of the grinding wheel by means of the adjusting, thumb screws 66 and 66'. Movement of the template in the plane of the grinding wheel is effected by movement of the longitudinal slide 31 'by means of the adjusting thumb screws 33 and 34 of the micrometer mechanism.

With continued reference to FIGURES 1 and 2, an upwardly-extending support plate 80 has an offset upper end portion 81 lying in a plane parallel to that of the longitudinal slide 31, and an L-shaped lower end portion 82 in engagement with a corner of the mounting block 10. One leg of the end portion 82 is secured to the vertical side Wall of the mounting block by means of the two fastening screws 83, see FIGURE 1. The other leg carries two locking screws, only one-such locking screw being visible in the top plan view of FIGURE 2, The fragmentary top plan view of FIGURE 6 shows the upper fastening screw 83 and the upper adjusting screw 84. The two fastening screws pass through clearance holes formed in the support plate leg 82, thereby providing for a slight adjustment of the support plate relative to the mounting yblock 10, as seen in FIGURE 8, which is a cross-sectional view taken along the line 8-8 of FIGURE 6.

Referring now to FIGURE 7, which is a full, vertical cross-sectional view taken along the line 7 7 of FIG- URE 6, there is shown a portion of the support plate 80, terminating in the lower end portion 82, and the two adjusting screws 84. A pair of locking screws 85 pass through clearance holes formed in the leg 82 and into threaded holes formed in the rear wall of the mounting block 10. By loosening these locking screws, slightly, as well as the other two fastening screws 83 shown in FIGURE 1, the support plate can be shifted, relative to the mounting block for the purpose of positioning the upper, offset end portion of the support plate (namely, the end portion identified by the numeral 81 in FIGURE 2), in a plane perpendicular to the cross slides of the grinding machine. Thereafter, the support plate is secured in such position by tightening the two locking screws 85 and the two fastening screws 83.

Referring to FIGURES 1 and 2, the support plate 80 carries a pair of vertically-disposed arms 88 and 89, the latter arm carrying a hand-operable knob 90 for rotation of `a. Vertical rod 91. A V-bar 92, carrying the stylus 93 and the diamond point 94, is removably secured to the rod 91 by means of a clamping fixture 95 provided with the two thumb screws 96 and 97, the construction of which will be described in detail hereinbelow. The lower end of the rod 91 passes through a bushing 98 carried by the lower leg of the arm 89, such leg being visible in FIGURE 1 and identified by the -numeral 163. The upper portion of the rod 91 passes through a hole formed in the horizontal leg 99, of an L-shaped bracket member 100, and is secured thereto by two cap screws 101. The upper portion of the rod 91 extends into a spacer bushing 105 and in alignment with a hole formed in the upper leg of the arm 89, such leg being identified by the numeral 162. The knob 90 is spaced from a plate i104 and enga-ges the upper end of the L-shaped bracket member 100, said knob being secured to this end of the bracket member by two screws 102, see particularly FIGURE 2. Rotation of the knob 90 results in a corresponding rotation of the rod 91 and the V-bar 92 secured thereto. The construction and assembly of the two arms 88 and 89 will be described hereinbelow. For the present, and with specific reference to FIGURE 2, it is pointed out that the arm 88 is carried by ya vertical block 106 secured to the offset end portion 81, of the support block 80, by four fastening screws 107 (see also FIGURE 3). This arm 88 is rotatable about a vertical axis identified by the letter (a) in FIGURE 2. The other arm 89 is rotatable about a vertical axis identied by the letter (b), and the stylus 93 is rotatable about the vertical axis (c). Thus, it will be seen that the described assembly affords rotary and linear movement of the stylus 93, thereby to trace the surface configuration of the template 65. A metal rod 108, carried by the arm 88, serves as 'a stop for engagement by the V-bar, thereby to prevent damage to the stylus, the diamond, or the pivot bearings which form the axis (b) in the event the knob and the arms are rotated to an extent such that the stylus and the point would otherwise strike against the arm 88.

Reference now is made to FIGURE 3, which is a fragmentary front elevational view corresponding to FIG- URE 1 but wherein the two pivotally mounted arms 88 and 89 are shown rotated to the in-line, or open position, and the knob 90 shown rotated 90 degrees from the position shown in FIGURE 1. This view shows the four screws 107 which secure the vertical block 106 to the offset upper end portion 81 of the support plate 80. A pivot pin 108 extends, snugly, through a clearance hole formed in the block 106 and has an end force-fitted into a hole formed in the end 81, see also FIGURE 9, which is a cross-sectional view taken along the line 9--9 of FIGURE 3. The fastening screws 107 pass through clearance holes formed in the block 106, thereby to permit a slight angular adjustment of the block about the pivot pin 108, the means for effecting such adjustment being described hereinbelow.

As shown in FIGURE 2, the vertical block 106 has an integral end portion 112 of increased thickness. This end portion is shown in FIGURE 3 and also in FIGURE 10, which is an enlarged, fragmentary cross-sectional view taken along the line -10 of FIGURE 3 and to which reference now is made. Formed in the end surface of the block 106 is -a vertical channel defined by tapered side walls 113, 114 and a at bottom wall 115. A clamping bar 117 has a generally similar channel formed therein, such channel, however, having a smaller depth than that formed in the block 106. A plurality of screws 118 pass through clearance holes formed in the clamping bar 117 and are threaded into holes formed in the block 106, thereby clampingly securing the pivot shaft 111 in fixed position. It will be noted that the pivot shaft, when clamped, engages the two side wal-ls of the channel formed in the block 106 and the bottom wall of the channel formed in the clamping bar 117, thereby assuring not only the positive securing of the shaft but also a precise location of the shaft relative to the block 106. The shaft 111 constitutes the pivot axis identified by the letter (a) in FIGURE 2 and the described clamping arrangement permits a vertical positioning of the shaft` without changing such axis, for purposes which will be described hereinbelow. Also shown in FIGURE 10 is the lower screw 144 for effecting an ,angular adjustment of the block 106 relative to the offset end 81, of the support plate. The head of this screw is disposed within a common bore formed in the said block and offset end, but the bore portion formed in the end 81 is deeper than that formed in the block. Thus, as viewed in FIGURE 10, tightening the screw 144 will result in the displacement of the block to the left. The screw 144, however, is positioned below the plane of FIGURE 10, see section line 10-10 in FIG- URE 3 so that the tightening of this screw actually -results in an angular displacement of the block 106 in a clockwise direction about the pivot pin 108. A similar screw 144 (see FIGURE 1l) is positioned at the upper end of the block 106, which screw, when tightened, results in a counterclockwise, angular displacement of the block 106 about the pin 108. Thus, these two screws can be manipulated to position the block 106 so that the pivot shaft 111, which is clampingly secured to the block, will be precisely perpendicular to the longitudinal slide of the grinding machine.

FIGURE l1 is an enlarged cross-sectional view taken along the line 11-11 of FIGURE 3, wherein there is shown the vertical block 106 which is secured to the offset upper end portion 81, of the support plate, the pivot shaft 111 and the fastening screws 118 which secure the clamping bar to the vertical block 106. It is pointed out that the pivot shaft extends above and below the block 106, las well as the clamping bar which has a vertical length equal to that of the said block. This view also shows the upper, horizontal cross bar 120 and the lower, horizontal cross lbar 121, which cross bars are members of the arm generally identified by the numeral 88 in FIG- URE 1. The shaft 111 extends substantially through the bushing 122, which bushing has a pair of concentric, circular grooves formed in its upper end surface. These grooves result in the axially-extending ring portions 116 and 119a. 'I'he lower surface of the cross bar 120 has a pair of concentric, circular grooves lformed in its lower surface, said grooves resulting in downwardly-extending ring portions 119 and 116a which fit into the circular 10 grooves formed in the bushing 122, see also FIGURE 12, which is a cross-sectional view taken along the line 12--12 of FIGURE 11. This construction IresultsI in an effective dust guard preventing deleterious matter f'rom entering to the pivot 124.

A short shaft 123, carrying a pivot 124, is disposed in a hole formed in the cross bar 120, said pivot being rotatable within the conical portion of an axial bore formed in the upper end of the pivot shaft 111. A plurality of relatively narrow grooves are formed in the conical surface of the bore, one such groove 126 being visible in this particular view. These grooves provide a ow path for oil from the bore to the surface of the pivot 124. A circular groove 127 may be formed in the inner wall of the bushing 122 for containing a conventional oil seal ring 127. A square end plate 130` is secured to the cross bar 120 by four screws 131, see FIGURE 2. Such end plate carries a screw 132 for adjusting the pressure between `the pivot 124 and the pivot shaft 111, said screw being retained in fixed position by means of the set screw 133. Another set screw 134 secures the shaft 123 to the cross bar.

The facing surfaces of the lower cross bar 121 and the lower bushing 135 also have mating, circular grooves and ring portions formed therein, thereby to form a lower dust guard. A pivot 136, carried by the shaft 111, operates within the conical portion of an axial bore 137 formed in the end of a short shaft 138, said conical groove portion having a plurality of narrow grooves 139 formed therein to provide an oil passageway from the bore to the pivot 136. A square end plate 140, secured to the cross bar 121, carries a screw 141 for adjusting the axial pressure between the shaft 138 and the pivot 136, said screw being secured in the adjusted position by means of a set screw 142. Another set screw 143 secures the shaft 138 to the cross bar 121. It will now be apparent that the long pivot shaft 111 is clampingly secured in xed position and that the two cross bars, together with the associated short shafts 132 and 138, are freely rotatable about a vertical axis defined by the two pivots. This is the axis identified by the letter (a) in FIGURE 2. Such axis is made precisely perpendicular to the slides of the grinding machine by adjustment, if necessary, of the vertical block 106 relative to the support plate 80, as has already been described with reference to FIGURE 3. The conical pivots 124 and 136, FIGURE 1l, preferably are hard chrome plated. With the oil grooves 126 and 139 formed in the conical portions of the bores which receive the pivots, each pivot has a bearing surface of a greater area than that of the conical portions. Consequently, any wear which may develop over a long period of use of the apparatus will take place in the conical surrfaces of the bores. This arrangement eliminates the possibility of developing wear spots -in the pivots which may alter the pivot axis.

Referring to FIGURE 3, the upper and lower horizontal cross bars 120 and 121 are secured to a center I-bearn by means of the two upper screws 146, 147 (see also FIGURE 2), and two similar lower screws 148, 149; Referring to the upper screws 146 and 147, these screws have their axes crossing at a 90 degree angle, and p'ass through clearance holes formed in the cross bar 120 and into threaded holes formed in the upper leg of the I-beam. The axial lines of these screws are odset along a plane normal to the paper and such lines cross in a plane containing the engaged surrfaces of the cross arm and upper leg of the I-beam, thereby forming, effectively, a hinge axis affording relative longitudinal displacement of the cross arm and leg in a horizontal plane, while maintaining the cross arm and leg in engagement with each other. Such relative displacement is accomplished by turning the two screws 146 and 147 in opposite directions. An angular adjustment of the cross arm 120 relative to the upper leg of the I-beam, about the hinge axis formed by the screws 1'46 and 147 and in a plane normal to the paper, is effected Iby means of two sets of adjusting screws, the forward screws of each set being identified by the numerals 150 and 152. Each of the screws 150 and 152 is disposed within a circular bore, and each bore is defined by a wall portion formed in the cross bar 120 and a wall portion formed in the upper leg of the I-beam. The associated adjusting screws which lie behind the cross bar 120 are Visible in FIGURE 2, it being noted that the screw 151 is aligned with the screw 150 and that the screw 153 is aligned with the screw 152. These screws 151 and 153 also have heads `disposed within individual Ibores formed partially in the cross bar 120 and partially in the upper leg of the I-beam, By manipulating the two sets of screws, a desired angular displacement of the cross arm relative to the I-beam can be effected in a horizontal plane and about the hinge axis formed by the screws 146 and 147. This particular adjustment arrangement is the same as that which has been described with reference to FIGURE 5 wherein the simultaneous rotation of the aligned screws 19 and 20 effects a displacement of the L-shaped mounting bracket leg 14 relative to the mounting block 10. The angular disposition of the fastening screws 146 and 147 assures a fiush engagement of the cross arm and the upper leg of the I-beam, irrespective of the angular setting of the cross arm. The lower cross arm 121 is similarly secured to the lower leg of the I-beam by the angularly-disposed fastening screws 148 and 149, and this cross arm is adjustable angularly by means of two sets of adjusting screws, the kforward such screws 157 and 158 being visible in FIG- URE 2,

'Carried by the right ends of the cross bars 120 and 121 is a pivot shaft and pivot assembly similar to that shown in FIGURE ll, corresponding parts of this assembly being identified by corresponding primed reference numerals. In this case, the clamping bar 117 is reversely disposed to the corresponding clamping Ibar 117 and the vertical block 106 has as mooth vertical side wall 160 to which the other arm 89, of the apparatus, is secured, as will be described hereinbelow. It is here pointed out that the aligned holes in the ends of the cross bars 120 and 121 (for receiving the short shafts, such as the shafts 123 and 138 shown in FIGURE ll) are formed simultaneously with the two cross bars held in absolute alignment in a suitable fixture. Consequently, the spacing of the holes in one cross bar is exactly the same as that of the holes formed in the other cross bar. It is, however, essential the axes of rotation for the two arms 88 and 89 be precisely aligned in all vertical planes. The pivot axis for the arm 88, formed by the pivot shaft 111, is aligned to be precisely vertical to the cross slides, or table, of the grinding machine by adjustment of the vertical bar 106 relative to the support plate 80. The described adjustment arrangements for the two cross bars 120 and 121, relative to the I-beam, are for the purpose of setting the pivot axis for the arm 89, formed by the pivot shaft 111', in precise alignment with the pivot axis of the arm 88.

To this point in the description, the second pivotallymounted arm has been generally identified by the numeral 89, see FIGURE 2. Actually, this arm comprises two separate L-shaped legs identified by the numerals 162 and 163 as shown in FIGURE 3. The upper leg 162 is secured to the vertical block 106 by the two fastening screws 164, which screws pass through clearance holes formed in the leg and into threaded holes formed in the block. Two sets of aligned adjusting screws are provided for effecting a desired displacement of the leg 162 relative to theI supporting block 106', in a horizontal plane, the forward screws of each set being visible in this view and identified by the numerals 165 and 166. This adjustment arrangement is similar to that which has already been described with reference to FIGURE 5. Referring to FIGURE l, two additional sets of adjusting screws 170 and 171 are threaded through holes formed in the leg 162, said screws having ends engaging the vertical side wall of the supporting block 106. These screws are spaced on either side of a vertical line passing through the two fastening screws 164. When these fastening screws areloosened, slightly, the adjustment of one or more of the screws and 171 results in a tilting of leg 162 relative to the supporting block 106'. Referring back to FIGURE 1, the lower leg 163, of the arm 89, is similar to the upper leg 162 but reversely disposed. Specifically, the lower leg 163 is secured to the supporting block 106' by two fastening screws 172, is laterally adjustable relative to the block by means of two sets of aligned adjusting screws (only the forward screws 173 and 174 of each set being visible in this particular view), and is tiltable relative to the block by manipulation of one or more of the adjusting screws 175 and 176.

The described arrangements for adjusting the positions of the two legs 162 and 163 relative to the supporting block 106 are for the purpose of aligning the rod 91 for rotation about an axis corresponding precisely to the pivot axes of the two arms 88 and 89. The lower end of the rod 91 carries a pivot 177 rotatable within the conical portion of an axial bore formed in the upper end of a short shaft 178, which shaft is supported by a square end plate 179 secured to the lower surface of the leg 163 by a plurality of screws. The upper portion of the rod 91 extends into the spacer bushing 105 and is aligned with a hole formed in the upper leg 162. The upper end of the rod 91 has a conical bore formed therein for receiving the pivot end of a short shaft 169. The described pivot arrangements are generally similar to `those described with reference to FIGURE l1. Although not shown in FIGURE l, the facing surfaces of the two legs 162 and 163 and the associated bushings 105 and 98 preferably are formed similarly to the corresponding members'ot` the FIGURE 11 assembly, thereby forming dust guards. It may here also be pointed out that the bushings 122 and 135', FIGURE 3, and the associated horizontal cross bars 120 and 121 are also constructed and arranged to form dust guards. Since the rod 91, FIG- URE 3, is secured to the horizontal leg 99 of the L-shaped bracket member 100, by the cap screws 101, rotation of the knob 90 results in a corresponding rotation of the rod about an axis identified by the letter (c) in FIGURE 2, which axis is precisely parallel to the axes (a) and (b). The V-bar is removably secured to rod 91 as will now be described.

Referring tto FIGURE l, the stylus 93, having a chiselshaped end for tracing engagement with the surface of the template 65, is secured to the V-bar 92, either by means of a forced fit or by set screws. A cutting tool 94 is similarly secured to theI V-bar and carries a diamond point for engagement with the grinding wheel 26 along a horizontal plane passing through the rotational axis of the grinding wheel. As has been described with reference to FIGURE ll, to which reference now is made, the long pivot shaft 111, which is clamped in a fixed position on the supporting block 106, may be shifted vertically upon loosening the clamping screws 118. Such vertical adjustment of the pivot shaft raises or lowe-rs the two cross bars 120 and 121, constituting members of the arm 89 (see FIGURE 3), without displacement of the pivot axis for such arm. This vertical adjustment of the pivot shaft results in a corresponding vertical displacement of the tool 94 (see FIGURE l), thereby to locate the diamond point precisely in the horizontal plane containing the rotational axis of the grinding wheel.

A longitudinal groove 180, of square cross-sectional configuration, see FIGURE l, is formed in the side wall of the V-bar 92, said groove being intersected by two transverse slots 181 and 182. A similar groove and similar slots are formed in the other side wall of the V-bar. The transverse slots form entrance passageways for the fingers 183 and 184, each finger having a downwardly-depending tip. The fingers 183 and 184 and the vertical connecting le-g 185 are formed from a single piece of metal and constitute one clamping arm of the fixture used to secure the V-bar to the rod 91. A similar clamping arm is dis- 13 posed along the other side of the V-bar, see FIGURE 3, wherein there are visible the vertical legs 185 and 185 of the two clamping arms forming the fixture. The two clamping arms are secured to two spacer blocks by the screws 187 and 188, the lower such spacer block 189 being shown in FIGURE 3.

FIGURE 13 is an enlarged cross-sectional View taken along the liney 13--13 of FIGURE 3 and shows the crosssectional configuration of the V-bar 92. Formed in the rear wall of the V-bar is a tapered channel 190, which channel extends the full length of the V-bar and receives the rod 91. The two vertical legs 185 and 185', of the clamping arms, are secured to the lower spacer block 189 by the screws 188 and the downwardly-directed tips of the corresponding fingers 184 and 184 are positioned within the longitudinal grooves 180 and 180 formed in the side walls of the V-bar. This lower spacer bar is provided with a threaded hole for the shank of the lower thumb screw 97 and the inner surface of the spacer block has formed therein an axially-extending, semi-circular channel of a radius somewhat greater than the rod 91. Also, the width of this spacer block is substantially equal to the transverse distance between the walls forming the bottoms of theI longitudinal grooves 180 and 180'. It will be clear that tightening of the thumb screw draws the V-bar into engagement with the rod 91,

Referring again to FIGURE 1, the V-bar is held against the rod 91, the fingers 183 and 184 are inserted along the transverse slots 181 and 182, the entire clamping fixture is moved downwardly along the rod 91 to thereby position the offset tips of the fingers in the longitudinal groove 180. Thereafter, tightening of the thumb screws 96 and 97 draws the V-bar firmly against the rod. The fastening screws 187 and 188 are not tightened to the point where they lock the two clamping arms to the fixture spacer bars, thereby affording a rocking movement of the two clamping arms as the thumb screws are tightened to draw the V-bar, tightly, against the rod 91. This rod is of substantial diameter, is centerless ground and hardened. The tapered groove formed in the rear wall of the V-bar is precision ground. The described rocking movement of the clamping fixture arms, during attachment of the V-bar to the rod, is to compensate for dimensional variations which may occur in machining the V-bar and distortion caused by heat-treating. The downwardly-directed tips of the clamping fixture fingers exert a uniform pressure at their contact points with the V-bar, when the screws 96 and 97 are tightened. Thus, the full length of the V-bar is in firm engagement with the rod 91, thereby eliminating errors which otherwise might arise by a twisting of the V-bar relative to the rod. A particular V-bar may be removed for touching up the diamond point, or replaced by another V-bar having a different diamond point, without disturbing the vertical axis about which the V-bar rotates upon rotation of the knob 90. Such axis is in precise alignment with the rotational axes of the various, pivotally-rnounted arms, as has been described.

The adjustment of the apparatus for imparting to the surface of the grinding wheel a configuration corresponding precisely to that of a template will now be described. The mounting block (FIGURE 1) is secured to the spindle housing of the grinding machine so that the longitudinal slide 31 is movable precisely parallel to the longitudinal slide of the machine. This movement of the longitudinal slide of the apparatus is checked by means of a suitable indicator mounted on a height gauge. Next, an indicator is attached to the lower cross bar 121, at the end carrying the plate 140' shown in FIGURE 3, said indicator having a point in engagement with the surface of the machine magnetic chuck. Upon rotating the arm A88, the gauge indication is noted as the point sweeps in an arc over the surface of the chuck. Assuming an initial difference in the gauge indications, for three positions of the point along a radial arc of 0-90 180 degrees, the vertical mounting block 106 and the support plate are adjusted, in a vertical plane, until repeated rotations of the arm 88 produce a constant gauge indication. Inasmuch as gauges of this type are readable to within one ten-thousandth of an inch (0.0001), the rotational axis of the arm 88 can be set so that it is precisely perpendicular to the surface of the grinding chuck.

The rotational axes of the other pivotally-mounted arm 89 (FIGURE 3) and the rod 911 are similarly checked, first by attaching the gauge to the lower leg 163 and thereafter to the rod 91. Normally, the adjustments necessary to set the rotational axes of this arm and the rod in precise alignment with the rotational axis of the first pivotally-mounted arm, are made at the factory and only minor changes in these adjustments may be necessary in the field, as when the apparatus is attached to a different grinding machine.

A test template now is secured to the cross slide 62 (FIGURE l) which template has a straight edge presented -to the stylus. The longitudinal slide 31 is adjusted so that the diamond point will just touch the surface of the grinding wheel when the stylus is in engagement with the template. Then, this slide is moved to the left to a desired extent, by means of the screws 33 and 34 of the micrometer mechanism. Now, upon movement of the stylus in tracing engagement with the straight edge of the test template, the diamond will dress the grinding wheel. The stylus now is moved away from the template and the grinding wheel brought into engagement with a test area formed on the machine chuck by pencil or blue ink. The purpose here is to remove a portion of the test area without producing sparking. In this way, it will be immediately apparent whether the peripheral surface of the grinding wheel is precisely parallel to the machine chuck. If not, appropriate adjustment is made in the straight edge of the template by means of the two adjusting screws 75 (see FIGURE 16). The wheel is redressed and its new surface checked by removing, without sparking, a new test area formed on the surface of the grinding chuck. This adjustment compensates for errors in the alignment of the cross slide and the wheel spindle of the particular grinding machine. It is here pointed out that this adjustment does not in any way affect the previous alignments made in the components carried by the support plate 80.

The test template now is replaced by a template having the desired configuration formed in the edge presented to the stylus. Since the ratio of movement of the stylus and the diamond point is 1:1, this template is made to full scale. Further, the template has a length substantially greater than the width of -the particular grinding wheel so that a considerable portion of the template is a straight edge. The cross slide 62, FIGURE 2, is moved, by means of the adjusting screws `66 and 66", to position the stylus so that the center of the configurated surface will lie in the vertical, median plane of the grinding wheel. Then, the longitudinal slide 31 is adjusted so that the diamond point will produce a desired depth of cut in the grinding wheel as the stylus is caused to trace the template surface. The depth of cut, when roughing a wheel with a roughing diamond, can range from 0.002 to 0.005 inch. With a finer-tipped diamond, after the roughing stage, cuts having a depth of l0.001 to 0.002 inch are made. For finishing the wheel, a line-pointed diamond can be used with a depth of cut from 0.00025 to 0.0005 inch. The lighter the cut made in the grinding wheel, the ner and more accurate will be the finish of the surface imparted thereto.

Having imparted the desired surface configuration to the grinding wheel, the wheel now is in condition for grinding a reciprocal configuration to -the surface of a work piece. Without removing the work :piece from the magnetic chuck, the apparatus is always in condition to retouch the wheel as may be required due to wear.

The construction and arrangement of the apparatus components, together with the described adjustment arrangements, makes it possible to produce on the work piece a configuration which corresponds to that of the template within an accuracy of $00002 inch.

The arrangement for mounting the apparatus on a grinding machine is not limited to a mounting block constructed as herein described. Other mounting arrangements may be utilized to secure the apparatus to the spindle housing of the machine. Also, the mounting7 arrangement may take various other constructions to permit mounting of the apparatus on the vertical housing of certain machines of the class wherein the wheel spindle extends from such housing.

Having now described the construction and features of the apparatus, those skilled in this art will be able to make various changes and modifications without thereby departing from the scope and spirit of the invention as recited in the following claims.

I claim:

1. Apparatus for imparting a predetermined configuration to the wheel of a grinding machine, Comprising,

(a) a mounting block for attachment of the apparatus to the machine,

(b) a support member secured to the mounting block,

(c) a first slide block secured to the support member and carrying a first slide member which is movable in a horizontal plane spaced above the grinding wheel,

(d) a second slide member carried by the first slide member and movable in a direction normal to that of the said first slide member,

(e) means operable to secure a template to the second slide member in a horizontal plane, which template has an edge of the predetermined configuration,

(f) a support plate secured to the said mounting block,

(g) a first arm member having one end pivotallycoupled to the support plate for rotation about a first vertical axis,

(h) a second arm member pivotally-coupled to the first arm member for rotation about a second vertical axis,

(i) a rod carried by the second arm member and rotatable about a third vertical axis,

(j) a tool bar carrying a tracing stylus and a diamond point, and

(k) means for securing the said tool bar to the said rod with the stylus disposed in the plane of the template and the diamond point disposed for engagement with the grinding wheel.

2. The invention as recited in claim 1, including cooperating adjustment means carried by the said mounting block and support member and operable to effect relative displacement of the block and support member in a horizontal plane.

3. The invention as recited in claim 2, wherein the cooperating adjustment means comprises at least one pair of adjusting screws threaded into aligned holes formed in opposed side surfaces of the said support member, each screw having an enlarged head disposed in a bore formed common to the support member and the said mounting block.

4. The invention as recited in claim ll, including cooperating means carried by the said first slide member and the said slide block and manually-operable to effect a calibrated movement of the said rst slide member relative to the said slide block.

5. The invention as recited in claim 4, wherein one of the said cooperating means comprises axially-aligned screws carried by the said slide block and another of said cooperating means comprises a fiat bar secured to the first slide member and extending between the said screws, and including a calibrated scale formed on the inner wall of the head of one of the said screws, and an index pointer secured to thc said fiat bar and cooperating with the said scale.

6. The invention as recited in claim 5, including an axially-movable tip carried by one of the said screws and spring means normally biasing said tip in the direction of said flat bar.

7. The invention as recited in claim 1, including means to adjust the orientation of the said first vertical axis with respect to the said support plate, means to adjust the orientation of said second vertical axis with respect to the first axis and means to adjust the orientation of the third vertical axis with respect to the second axis.

8. The invention as recited in claim 1, including adjusting means carried by the second slide member and operable to adjust the position of the template in its horizontal plane.

9. The invention as recited in claim S, including vertically-spaced ledges extending from the second slide member, the lower ledge supporting the template; means carried by the lower of said ledges and operable to lock the template against movement in a horizontal plane; means carried by the upper of said ledges and operable to lock the template against movement in a vertical plane; and wherein the said adjusting means carried by the sec* ond slide member comprises a pair of screws carried by the second slide member and having ends engageable by an edge of the template.

10. The invention as recited in claim 1, wherein the said first vertical axis is constituted by a first verticallydisposed shaft having a conical bore formed in the upper end and a pivot at the lower end, said shaft being secured in fixed position relative to the said support plate; a second shaft carried by the said first arm member and having a pivot end disposed in the conical bore of the first shaft; a third shaft secured to the said first varm member and having formed therein a conical bore receiving the pivot of the said first shaft.

11. The invention as recited in claim 10, including means to adjust the axial pressure between the first shaft and the other two shafts.

12. The invention as recited in claim 1, including a knob disposed above and rotatably carried 'by the said second arm member, said knob being secured to the said rod to effect rotation thereof about the said third vertical axis.

13. The invention as recited in claim 1, wherein the said tool bar has a tapered groove formed in the rear wall, matching longitudinal grooves formed in the side Walls and transverse slots intersecting said longitudinal grooves, and wherein the said means for securing the tool bar to the rod comprises two clamping plates spanning the said rod, each such plate having spaced ngers with offset ends slidably insertable into the said longi` tudinal groove; a pair of spaced blocks secured to the end portions of the said clamping plates and having arcuate grooves formed therein; and thumb screws carried by the said spacer blocks and having ends for engagement with the said rod, the recited arrangement being such that tightening of the thumb screws clampingly secures the tool bar to the said rod.

14. The invention as recited in claim 13, including a manually-operable knob disposed above the said second arm member; an L-shaped bracket member having a horizontal leg spaced from the lower surface of said second arm member and a vertical leg spaced from an end of said second arm member; means securing the knob to the said vertical leg and means securing the said rod to said horizontal leg.

1S. The invention as recited in claim 1, wherein the said first arm member comprises a center Ifbeam having horizontally-disposed upper and lower legs; an upper cross bar in engagement with the said upper leg; a lower cross bar in engagement with the said lower leg; a first pair of fastening screws passing through clearance holes formed in said upper cross bar and into threaded holes formed in said upper leg, said screws having axes which cross in a horizontal plane containing the engaged surfaces of the upper cross bar and upper leg, thereby forming a first hinge axis; a second pair of fastening screws passing through clearance holes formed in said lower cross lbar and into threaded holes formed in said lower leg, said screws having axes which cross in a horizontal plane containing the engaged surfaces of the lower cross bar and lower leg, thereby .forming a second hinge axis; first adjustment means to eiiect an angular displacement of the upper cross bar about the said first hinge axis; and a second adjustment means to effect an angular dis- 18 placement of the lower cross bar about the said second hinge axis.

References Cited UNITED STATES PATENTS 2,151,802 3/1939 Roman 125-11 2,187,690 1/ 1940 Martin 125--11 2,469,365 5/ 1949 Braaten 125--11 2,725,049 11/ 1955 Jakobsen 125--11 2,832,330 4/1958 Hughes 125-11 2,926,653 3/1960 Krafft 125--11 OTHELL M. SIMPSON, Primary Examiner. 

1. APPARATUS FOR IMPARTING A PREDETERMINED CONFIGURATION TO THE LEVEL OF A GRINDING MACHINE, COMPRISING, (A) A MOUNTING BLOCK FOR ATTACHMENT OF THE APPARATUS TO THE MACHINE, (B) A SUPPORT MEMBER SECURED TO THE MOUNTING BLOCK, (C) A FIRST SLIDE BLOCK SECURED TO THE SUPPORT MEMBER AND CARRYING A FIRST SLIDE MEMBER WHICH IS MOVABLE IN A HORIZONTAL PLANE SPACED ABOVE THE GRINDING WHEEL, (D) A SECOND SLIDE MEMBER CARRIED BY THE FIRST SLIDE MEMBER AND MOVABLE IN A DIRECTION NORMAL TO THAT OF THE SAID FIRST SLIDE MEMBER, (E) MEANS OPERABLE TO SECURE A TEMPLATE TO THE SECOND SLIDE MEMBER IN A HORIZONTAL PLANE, WHICH TEMPLATE HAS AN EDGE OF THE PREDETERMINED CONFIGURATION, (F) A SUPPORT PLATE SECURED TO THE SAID MOUNTING BLOCK, (G) A FIRST ARM MEMBER HAVING ONE END PIVOTALLYCOUPLED TO THE SUPPORT PLATE FOR ROTATION ABOUT A FIRST VERTICAL AXIS, (H) A SECOND ARM MEMBER PIVOTALLY-COUPLED TO THE FIRST ARM MEMBER FOR ROTATION ABOUT A SECOND VERTICAL AXIS, (I) A ROD CARRIED BY THE SECOND ARM MEMBER AND ROTATABLE ABOUT A THIRD VERTICAL AXIS, (J) A TOOL BAR CARRYING A TRACING STYLUS AND A DIAMOND POINT, AND (K) MEANS FOR SECURING THE SAID TOOL BAR TO THE SAID ROD WITH THE STYLUS DISPOSED IN THE PLANE OF THE TEMPLATE AND THE DIAMOND POINT DISPOSED FOR ENGAGEMENT WITH THE GRINDING WHEEL. 